1. Field of the Invention
This invention relates to processes and apparati for harvesting crustaceans and, particularly, soft shell crustaceans such as crayfish.
2. Prior Art
In the the past, crayfish have been harvested principally in the swamps and marshes of coastal regions by the use of baited traps. However, as demand has grown, commercial "farms" for the growing of crayfish have developed. Until recently, the harvesting of these farms was done by the conventional baited traps. However, the baited traps have several disadvantages which have slowed the successful commercial development of these "farms".
Because of the size of the commercial farm ponds, many traps are required to harvest the crayfish; thus, the yield per acre have made many "farms" unprofitable. This has led to extensive research for better baits and other means of harvesting. One such means has been experimental mechanical devices which, much like grain combines, attempt to scoop up the crayfish as the devices move across the field. These devices have also been plagued by problems inherent in the nature of what crayfish ponds must be like, i.e., vegetation, such as rice and algae growing throughout, as well as the shallow depth of the pond.
Another problem is the fact that crayfish tunnel underground to build their homes, and if there are logs or stones in the pond, the crayfish have a tendency to build next to such obstacles or in the vegetation in the pond. This, in turn, has created problems for mechanical harvesters.
Soft shell crayfish pose an even greater problem since they rarely stray far or for long from their home or they stay in the pond vegetation as they are very vulnerable to predators until their shells harden. However, it has long been recognized that if they could be harvested, they would be an immediate commercial success since the entire crayfish could be eaten rather than just the tail meat which comprises only ten to fifteen percent of the body weight.
For all of the above reasons, harvesting of soft shell crayfish in sufficient numbers has been impossible until this invention.